钼在不锈、耐热、耐酸等钢和合金中,经常可有2～6％的含量,虽有重量、容量等较好的测定方法,但因都需繁琐的分离,故测定的周期冗长,在日常分析中颇感使用不便,而硫氰酸盐直接光度法,则又因干扰离子较多且络合物色泽不甚稳定,一般不适用于>2％的含量测定。 氯代磺酚C作为铌的显色剂,人们已作了很多研究,但应用于其它元素的测定研究还不多见。 资料曾介绍用氯代磺酚C在pH0.9～2.5的硫酸介质中直接测定生铁和钢中的钼量,但铌、钒、钨、铜、铝……,特别以铌、钒的干扰。较为严重。 本文通过试验,发现显色液的酸度是方法选择性的关键,在0.6N盐酸介质中用抗坏血酸还原铁,再对含钨铌试样辅之以简单 Molybdenum in stainless steel, heat-resistant, acid-resistant steel and alloys, often 2 to 6% of the content, although the weight, capacity and other better determination, but because of the need for tedious separation, so the measurement of the lengthy , In the daily analysis quite inconvenient to use, and thiocyanate direct photometry, then due to more interference ions and complex color is not stable, generally not applicable to the determination of> 2%. Chlorosulfonates C as a chromogenic reagent of niobium, many people have made a lot of research, but applied to the determination of other elements of the study is rare. Data have been introduced with chlorosulfonamide C in sulfuric acid at pH0.9 ~ 2.5 direct determination of the amount of pig iron and steel molybdenum, but niobium, vanadium, tungsten, copper, aluminum ... ..., especially niobium, vanadium interference. More serious. In this paper, we found that the acidity of the chromogenic solution is the key to the selectivity of the method. In the medium of 0.6N hydrochloric acid, iron is reduced by ascorbic acid, and the sample containing tungsten and niobium is supplemented by simple